Clone fails on a repo with too many heads/tags

The full description of the problem can be found in the first patch.

Changes since v2:

* fix a bunch of code style and documentation issues spotted by Junio
* tighten ref format checking on stdin to not allow extra whitespace
* make fetch-pack --stdin tests independent of the order of refs
* add test for duplicate refs on stdin
* drop the two ugly and redundant --stateless-rpc tests
* drop the test that tolerated extra whitespace

Changes since the original patch:

* add test cases
* add full commit messages
* fix formatting problem in --stdin doc
* split overly long fetch_pack_usage line
* use strbuf_getline() instead of fgets() for reading refs from stdin
* minor optimization of the pkt-line reading loop, it was using xstrdup() even though the string length was already known, use xmemdupz() instead
* rework the remote-curl.c patch to not add new parameters to rpc_service(), instead add a new strbuf member to rpc_state to pass the info around

Ivan Todoroski (4):
fetch-pack: new --stdin option to read refs from stdin
remote-curl: send the refs to fetch-pack on stdin
fetch-pack: test cases for the new --stdin option
remote-curl: main test case for the OS command line overflow

 Documentation/git-fetch-pack.txt |   10 ++++++
 builtin/fetch-pack.c             |   42 +++++++++++++++++++++++-
 fetch-pack.h                     |    1 +
 remote-curl.c                    |   14 ++++++--
 t/t5500-fetch-pack.sh            |   66 ++++++++++++++++++++++++++++++++++++++
 t/t5551-http-fetch.sh            |   31 ++++++++++++++++++
 6 files changed, 161 insertions(+), 3 deletions(-)

1.7.9.5.4.g4f508